Solved: small enough to be deployed on a phone
Got it. In case others run through these issues, here's my flow to get Phi3 running in ollama, in CPU-only mode, on a Whiskey Lake i3 (2 SMT cores), connected to the web via a 3G/4G smartphone. It takes about 2.6 GB of downloads, and maybe 5 or 10 GB of disk space (2.8 GB wasn't enough it seems).
1. download and "install" ollama (290 MB) from its website, into a folder of your choice, following manual instructions (without systemd autostart and such; precede commands with "sudo" if needed/wanted):
curl -L https://ollama.com/download/ollama-linux-amd64 -o ollama
chmod +x ollama
2. download the CPU-only version of Phi3 (2.3 GB) from Hugging Face, the file is named: Phi-3-mini-4k-instruct-q4.gguf (download straight from the website to avoid the "Error: max retries exceeded"), save it in the same folder as ollama.
3. in that same folder, create a text file named buildPhi3 (for example) that contains the single line:
FROM Phi-3-mini-4k-instruct-q4.gguf
4. run ollama to build the Phi3 model (that will go in your home folder, eg. under /home/you/.ollama/models ... you need some free disk space there, or make symlinks to another place):
./ollama create Phi3 -f buildPhi3
5. test that your Phi3 works with a simple prompt: "What is The Register?":
./ollama run Phi3 "What is The Register?"
Voila! Tobias' 10-minute HowTo has more of course. Either way, one should be able to prompt engineer his/her hacking future better from thereon in, or out (at 4x 100% CPU utilization, 5 GB of SDRAM in use!).